In recent years, particularly from the view point of protection of the earth environment, expectation for solar cells that convert sunlight energy into electric energy as a next-generation energy source has been rapidly increased. While various types of solar cells including those using a compound semiconductor and those using an organic material are known, solar cells using silicon crystals are the current mainstream.
The solar cells that are most widely produced and on the market at present have such a structure that an n electrode is formed on the surface where the sunlight enters (light-receiving surface), and a p electrode is formed on the surface opposite to the light-receiving surface (back surface).
For example, Patent Literature 1 (Japanese Patent Laying-Open No. 2005-310830) discloses a back electrode type solar cell wherein an n electrode and a p electrode are formed only on the back surface of the solar cell while no electrode is formed on the light-receiving surface of the solar cell.